15
Figure 6.4: PA structure
Definition of main pin: spec value of working voltage VBAT1
、
VBAT2 is 3.5V, provided by battery of mobile
phone. TX-EN is the power set of amplifier, at high level is (1.9V
～
3.0V
，
spec level 2.0V), at low level is (0V
～
0.5V
，
spec value 0V). GSM band select pass, at high level
（
1.9V
～
3.0V
，
spec value 2.0V
）
, DCS band select
pass. VRAMP is frequency modulate control level, around 0.2V-1.8V
图
7.1
：
W420
基带电路原理示意图
Figure 7.1: W420 base band circuit structure
Figure 7.1 shows basic control flow of W420 mobile phone
It is shown in the picture that U201 is the core of control in the whole system. It carries out all programs
storage in U307, and control the whole system through U202, U304 and U302
According to the difference of function, W420 can be divided as: RF process circuit (including receiver part
and transmit part), audio interface circuit (Mic
、
Receiver
、
ear phone Mic and ear phone Receiver) and charge
RF313
3
(PA)
MIC
Speak
er
Receiver
T-Flash
M-DOC
Bluetoot
h
IrDA
U202
TWL3016B2G
WQ
(ANALOG
BASEBAND)
U201
OMAP 730
Earphone
Supply
Management
BQ24026
LCD
2M
Camera
TRF6151CRGA
(transcevier)
U307
S-DRAM
Summary of Contents for W420
Page 1: ...Voxtel Repair Manual Item W420 ...
Page 23: ...23 3 LDO circuit ...
